Hoisting apparatus.



No. 819,140. PATBNTBD MAY l, 1906. W. F. HUNT a R. J. ROBERTS.

HOISTING APPARATUS."

APPLIGATION FILED JAN. 2o, 1905.

Unirse srnfrns Parana? ernten.

WILLlAM F. HUNT ND ROBERT JEFFRIES RQBERTS, OF NEW YORKJN. Y.

HolsTlNe APPARATUS.

Specification of Letters Patent.

atenten May 1, 1906.'

Application filed January 20,1905. Serial No. 241,915.

Z'o all whom, it may concern:

Be it known that we, NiLLIAM F. HUNT and ROBERT Jnrrnrns ROBERTS,citizens of the United States, residing in Vest New Brighton, in theborou h of lichmond, of the city of NewYork, in t 1e State of New York,have invented certain new and useful Improvements in Hoisting Apparatus,of which the following is a specification, reference being had to theaccompanying drawings, forming a part hereof.

This invention relates to hoisting apparatus of the general character ofthat commonly employed for discharging coal and other like urposes inwhich two drums are provided ihr winding and unwinding the ropes whichraise and lower and also control the opening and closing of the shovelor scoop. Such hoisting apparatus is commonly driven by a steam-engineand is controlled by three levers7 one, usually a foot-lever,controlling the throttle of the steam-engine, and the other twocontrolling the friction-clutches through which the two drums are drivenfrom the engine. The desirability of substituting electricity as themotive power in many installations of this character 1s obvious; but ithas thus far proved impracticable for most installations because of thegreat cost of installing an efficient motor control by which it shall beossible to vary the power of the motor, as t e power of the steam-engineis controlled b throttling, so that theload may be starte slowly and itsmovement controlled as desired. It is impracticable to rely simply uponthe usual riction-clutehes for the two drums because of the excessiveheating which would be developed7 the motor running continuously.

It is the object of the present invention to render practicable theapplication of the continuous v-operating motor, such as an electricmotor, to the operation of such hoisting apparatus while avoiding thedifliculties and objections above referred to and without requiringTfurther increase in the number of controlling-levers. It is undesirableto increase the number of, controlling-levers, for the reason that three'levers are all that can be properly managed by one operator.

1n accordance with the invention each hoisting-drum is driventhrough itsown friction-clutch or equivalent variable driving means from thetransmission mechanism, and between the transmission mechanism and themotor is a third friction-clutch or equivj alent variable driving means.By the interposition in this manner of two friction- Y clutches betweenthe motor and each drum it is possible to divide the total slip betweenthe two friction-clutches so that the amount of heating in either clutchis not excessive. The use of a friction-clutch between the motor and thetransmission mechanism, however, deprives the apparatus of the=resistance which is offered by the steam-engine in a steam-drivenapparatus for purposes of braking when the drums are stationary or arepermitted to rotate in a reverse direction, since the friction-clutchbetween the motor and the transmission mechanism must be whollydisconnected at such times. As already stated, it is impracticable toadd a separate brake for the transmission mechanism to be controlled bythe operator, and it therefore becomes necessary to give thetransmission mechanism such a character that it will automaticallyresist backward movement. Obviously this may be accomplished bydifferent means, one convenient form of such means being represented inthe accompanying drawings, in which a practical embodiment of theinvention is illustrated for purposes of explanation of the naturethereof.

ln the drawings, Figure l is a view, partly in plan and partly inhorizontal section, of a hoisting apparatus which embodies the in-lvention. Fig. 2 is a side elevation of the same.

ln the en'lbodiment of the invention which is illustrated in thedrawings the two drums a and I), having the hoisting-ropes wound aboutthem, are represented as mounted loosely upon a common shaft c. Thelatter is shown as supporting also a worm-wheel (l, which may havesecured thereto or formed therewith two friction-clutch members d andd2, which coperate, respectively, with the corresponding clutch membersa and b' ol' the drums (L and b. Each drum isadapted to be moved into orout of engagement with the common gear through the frictionclutch by acontrolling-lever e, acting through a rock-shaftf, a system ol' linksand levers g, and screws 11, as usual in hoisting apparatus of thecharacter to which the iuvention relates.

The two friction-clutches or other variable driving means for the twodrums are driven by a transmitting mechanism which comprises in theembodiment ol the invention illustrated the worm-wheel d above mentionedIIO and a worm i upon a shaft 7c, these parts constituting a convenientform of transmitting mechanism which is non reversible in the sense thatit resists backward movement from the load. The shaft 7c carries onemember Z of a friction-clutch or other variable driving means, the othermember 'm of which vis keyed upon the shaft n, driven by the niotor orsource of power o through a reducinggear fp. The movable clutch member,which in this insta-nce is shown as the member ym., is represented'ascontrolled through a lever g from a foot-lever r, which is convenientlyvplaced with relation to the hand-levers e, so that one operator cancontrol all three of the clutches as the conditions ot' operation mayrequire. Y

ln the operation of the apparatus, it being understood that the motor ois running continuouslv, the operator, pressing upon the lever i, throwsin the clutch Z m, and imparts motion to the transmitting mechanism.Then by operation of Ythe levers c one or the other, or both, of thedrums (L and l) are made to rotate at speeds which are determined by theengagement of the clutches a. d and o Abt. it itis desired to stop themovement of the shovel, the clutch l Imis opened and both clutches a dand lf2 are closed, the resistance necessary to hold the drums a. and bfrom rotation under the tension of the load being furnished by thetransmitting mechanism which, as previously indicated, is ol such acharacter as to prevent movement in a. re verse direction. Suchunwinding ol either or both hoisting-ropes as may be necessary ispermitted by releasing'one or the other, or both, of the drum-clutches,and it will be obvious that b y proper manipulation oi' the clutches anvdesired'movement ma)r be imparted to the shovel. l `urtbermore, asalready pointed out, the motor may be allowed to rotate continuously, noundue heating of an)v clutch is necessarily occasioned under anyconditions o1C operation, and the whole apparatus is under the controloi a single operator through three controllinglevers. l

it will be obvious that various changes can be made in details ol'construction and arrangement without departing from the spirit of theinvention.

We claim as our invention-n 1. 'lhe combinatiomin a hoisting apparai I l1 tus, of a source of power, two hoisting-drums, independent variabledriving means interposed between the source of power and the drumsrespectively whereby either of said drums may be driven independently ofthe other, a third `variable driving means interposed between the sourceof power and the iirst named variable driving means, and means forpreventing the reverse rotation of the Yfirst-named variable drivingmeans, substantially as described.

2. The combination, in a hoisting apparatus, of a source of power, twohoistingdrums, independent clutches interposed between the' source oi4power and the drums respectively whereby either of said drums may bedriven independently of the other, a third clutch interposed between thes ource of power and the vfirst e named clutches, and means forpreventing the reverse rotation ot the tiret-named clutches,substantially as described.

3. A hoisting apparatus comprising two drums, a non-reversibletransmitting mechanism, clutches interposed between the drums and thetransmitting mechanism, a motor, a clutch interposed between the motorand the transniitting mechanism, and means to control said clutch,substantially as described.

el.. A lmisting apparatus comprising two drums, a non-reversibletransmitting mechanism having a gear common to both drums, clutchesinterposed between said gear and said drums, a motor, a clutchinterposed between said motor and the transmitting niechanism and meansto controlsaid clutches, substantially as'described.

5. A hoisting apparatus comprising two drums, a worm-gear common te bothdrums, independent clutches interposed between said gear and said drumswhereby either of said drums mayr be driven independently of the other,a worm-shaft, a motor, a clutch interposed between the said motor andthe worm shaft and means to control said clutches, substantiall)T asdescribed.

This specification signed and witnessed this 'lth day oidanuary, A. D.1904.

wu. r, HUNT. ROBERT JEFFHHS ROBERTS. ln presence of* W. B. Generar, M.A. BRAYLEY.

